xray-rust v0.4.0

Highlights

• Added Apple VLESS share-link import for xhttp/splithttp with plaintext,
  TLS, or REALITY transport security. The importer preserves supported
  security fields, handles bounded single- or double-percent-encoded extra
  JSON, and rejects unsupported non-empty certificate-pin/ECH settings instead
  of silently downgrading them.
• Implemented Xray-compatible one-level XHTTP extra replacement semantics,
  while keeping outer host, path, and mode. The removed
  scMaxConcurrentPosts field remains import-compatible but is ignored rather
  than being misread as scMaxBufferedPosts.
• Reduced plaintext HTTP/1.1 XHTTP packet-up memory pressure. Uplink buffers
  now grow in 8 KiB steps only when data is available and reuse their actual
  allocation instead of reserving or cloning the configured maximum POST size
  for every active flow.
• Added an exact legacy-profile RSS benchmark with held-flow, 16 KiB control,
  settle, and ACK-gated rollover phases. The recorded 16-flow macOS run showed
  a 96 KiB median RSS delta between a 500000-byte max-POST profile and the
  otherwise identical 16384-byte control.
• Updated h2 to 0.4.16 for its upstream RustSec fix and refreshed the
  transitive chacha20 lock entry to 0.10.2 after 0.10.1 was yanked.

Compatibility boundary

This release supports XHTTP share links with VLESS encryption=none and no
Vision flow. Effective XHTTP downloadSettings, non-empty modern TLS
certificate-pin/ECH fields that the current Rust model cannot honor, and
non-none VLESS encryption remain fail-closed.

The separately packaged Apple/Android SDK release will follow in
xray-rust-mobile v0.4.0.